What are the findings?
There is a large, well circumscribed extra-axial parafalcine mass with a lobulated margin on the right, with associated mass effect and midline shift to the left. The mass is hypointense on T1, hyperintense on T2 and has homogenous enhancement on T1 C+ weighted imaging. The mass has a broad falcine base and appears to arise from the falx cerebri.
What are the features of meningioma on MRI?
Extra-axial mass, with a broad base. Well circumscribed and homogenous. Signal characteristics include: T1 - isointense or hypointense T1 C+ (Gd) - usually intense and homogenous enhancement T2 - Mostly isointense or hyperintense DWI - atypical and malignant sub types may show greater than expected restricted diffusion. Chordoid meningiomas usually demonstrate facilitated diffusion.
How is an extra-axial mass differentiated from an intra-axial mass?
The cleft sign - a cleft of signal hyperintensity between the mass and surrdounding parenchyma on FLAIR imaging suggests extra-axial location.
There is a large, well circumscribed extra-axial parafalcine mass with a lobulated margin on the right, with associated mass effect and midline shift to the left.
The mass is hypointense on T1, hyperintense on T2 and has homogenous enhancement on T1 C+ weighted imaging. The mass has a broad falcine base and appears to arise from the falx cerebri. The majority of the mass demonstrates pronounced facilitated diffusion, with even the most restricted area showing ADC values still higher than adjacent brain.
The findings suggest meningioma.